Reporter: dave-openstreetmap[at]earth.li
[Submitted to the original trac issue database at 2.31pm, Saturday, 25th March 2006]

The threads that recieve responses from the server directly modify the lines Map in the applet. This map is also iterated through with a fail-fast iterator. We should probably do something to stop the concurrent access, like synchronising the accesses on the map. A good start would be to make the map private and encapsulate the accesses to it. We could then control all of the locking in one place.

I have written a patch that reduces the amount this happens, but it doesn't solve the problem completely.